Presentation Detail

Species Interactions and Coevolution

Greenspoon, Philip Benjamin [1], M'Gonigle, Leithen [2].

The evolution of mutation rate in an antagonistic co-evolutionary model with maternal transmission of parasites.

Mutation is crucial for adaptation, as it is the source of new variation. Because most mutations are deleterious, mutation rates should evolve to zero. However, non-zero mutation rates characterize all species. By constantly selecting for novel genotypes, coevolution between hosts and parasites maintains non-zero mutation rates. Models of this process typically assume random encounters. However, offspring are often more likely to encounter their mother's parasites. Because parents and offspring are genetically similar, they may be susceptible to the same parasite strains and thus, in hosts, maternal transmission should select for mechanisms that decrease intergenerational genetic similarity. In parasites, however, maternal transmission should select for genetic similarity. We develop and analyse a model of host and parasite mutation rate evolution when parasites are maternally inherited. In hosts, we find that maternal transmission has two opposing effects. First, it eliminates coevolutionary cycles that previous work shows select for higher mutation. Second, it independently selects for higher mutation because offspring that differ from their mothers are more likely to avoid infection. In parasites, coevolutionary cycles similarly select for higher mutation, whereas, maternal transmission selects against it.

1 - Stanford University, Biology
2 - University of California, Berkeley, Department of Environmental Science, Policy, and Management

Keywords:
parasites
mutation
Coevolution
modifier model
maternal effects.

Presentation Type: Regular Oral Presentation
Session: 99
Location: Cotton B/Snowbird Center
Date: Monday, June 24th, 2013
Time: 9:00 AM
Number: 99003
Abstract ID:119
Candidate for Awards:W.D. Hamilton Award for Outstanding Student Presentation